|Series|Start date|End date|Episodes|
|---|---|---|---|
|1|29 October 1986|31 December 1986|10|
|2|15 April 1987|24 June 1987|10|
|3|17 September 1987|28 January 1988|20|
|4|4 October 1988|14 February 1989|20|
|5|25 December 1989|4 June 1990|21|
|6|25 September 1990|12 February 1991|21|
|7|23 September 1991|26 December 1991|13|
|8|21 September 1992|28 December 1992|12|
|9|27 September 1993|27 December 1993|14|
|10|13 September 1994|29 December 1994|14|
|11|12 December 1996|3 April 1997|16|
|12|8 September 1997|29 December 1997|16|
|13|17 September 1998|31 December 1998|16|
|14|7 June 1999|23 August 1999|12|

Question: how many epiodes are in series 1-3 combined?
Answer: 40